32-bit vs. 64-bit

32-bit hardware and software systems, at times referred as x86 or x86-32, work with data in 32-bit pieces. In contrast, 64-bit hardware and software systems, or x64 or x86-64, use data in 64-bit pieces. Theoretically, the more data in general that can be processed at any one time, the faster the system can perform.

An immediate practical advantage that 64-bit systems offer is the use of greater amounts of RAM. Most new computer systems today include new processors based on 64-bit architecture. While it is obvious that these systems support 64-bit operating systems, they are also compatible with 32-bit operating systems. The converse is not true viz. 32-bit hardware cannot support 64-bit operating systems.

32-bit and 64-bit are terms referencing on how a processor embedded in the computer, or CPU, handles data. A 32 bit architecture allows the arithmetic and logic unit (ALU), or digital circuit, to perform 32-bit integer arithmetic and logical operations.

For architecture with 64-bits, it allows a 64-bit version of Windows to handle large amounts of RAM better than a 32-bit system. Also a 64-bit system has 64-bit address registers, with data registers and the data bus typically equivalent in size as the address registers. So, 64-bit CPU and ALU architectures have matching registers and address, or data, buses in like values.

A 32-bit processor cannot run an operating system designed for 64-bit CPUs. Nor does it support 64-bit applications. 32-bit CPUs can only run a 32-bit OS and applications designed for 32-bit operating systems.

32-bit systems have a limitation on how much memory they can address (or point to). This limit is 4GB. While memory usually refers to RAM, this limit also includes memory in the other devices in the system like video, audio and network adapters. The combined limit for RAM,graphics(GPU) RAM, PCI memory range and a few other components is 4GB.[1]

The practical implications of this are that 32-bit Windows, for example, cannot take full advantage of 4GB RAM, and it typically shows 3.25GB. Installing more RAM is always an option, but 32-bit systems would simply not be able to use any RAM over its limit. A 64-bit version can address up to 8TB. With current systems unable to take full advantage of capacity, systems now are available with installed RAM far exceeding the 4 GB limits of 32-bit systems.

When using a virtual private server (VPS) like Linode or DigitalOcean, system administrators are often constrained by how much RAM is available. So they often recommend using a 32-bit Linux distribution to use on a VPS rather than a 64-bit operating system.

Ability to use more RAM. 64-bit processors are theoretically capable of referencing 2^64 locations in memory, or over 4 billion times the memory numbers 32-bit processors can reference. Current 64-bit Windows OS 16 TB limit, with no more than 128 GB of physical RAM due to impracticality. As a result, 64-bit processes can create 16TB of virtual, through 8 TB allotted in virtual memory for user processes and 8 TB for kernel processes.

More efficiency. When additional RAM is installed, 32-bit systems usually cannot take advantage of it because of the addressable space limits. But 64-bit systems can, which often results in significant performance boosts.

More virtual memory allocation. 64-bit architecture Windows can theoretically offer 8 TB of virtual memory to an application. 32-bit architecture Windows is limited to 2GB. The modern applications, especially for games, video and photo editing, desire more RAM. With the 64-bit efficient use and allocation of memory, those applications optimized for the 64-bit OS can take full advantage of the new space.

Possible driver compatibility. While there is increasing support for 64-bit OS, for those still embracing older, solid, and often still functional hardware, a transfer will be in order, and sooner than later. It is unlikely that 64-bit drivers will be available for older systems and hardware. These are decisions made case by case.

Some motherboard RAM limits. A rare occurrence is finding a motherboard supports early 64-bit processors, but not offer support more than 4GB of RAM. What is available can be some benefits of a 64-bit processor, albeit without access to more RAM. It might be time to upgrade your OS.

Legacy issues. Software will likely not make a transition to 64-bit processing. Older applications, including 16-bit applications, will require virtualization. Otherwise, it might be time for an upgrade.

Windows 8, both with its Standard and Pro versions, is available in 32-bit and 64-bit distributions. Prior to its launch of Windows 7, Microsoft stated that its Windows 8 would be the last Windows to support 32-bit architecture. With the final move of its apps, drivers and plug-ins to 64-bits, Windows will not provide 32-bit backwards compatibility. For present systems still requiring Windows XP support, it can be found through sandboxed virtualization, which was done in Windows Server 2008.

Subsequently, computers will need 64-bit-capable processors. If you are using Windows, you can check whether your processor is 64-bit by doing the following :

Open Performance Information and Tools by clicking the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Performance Information and Tools.

Click View and print details.

In the System section, check the OS type currently running under System type. For 64-bit capable, it shows if the system can run 64-bit Windows.

Note: if the system is already running a 64-bit Windows version, a 64-bit capable listing will not be shown.